#include <cstdlib>
#include <iostream>
int fact(int a)
{
    int r;
    if(a == 1)
    {
        r = 1;
    }
    else
    {
        r = a * fact(a - 1);
    }
    return r;
}
int main(int, char**)
{
    std::cout << fact(12) << std::endl;
    return EXIT_SUCCESS;
}
